Field of the Invention
The present invention relates to a device which determines which electrical wire bundle is to be used for an electrical test when the test is performed using connection information on a large number of wires in which a plurality of electronic devices are interconnected via connectors through wire harnesses including electrical wires.
Description of the Related Art
A wiring system which is configured by interconnecting, for example, an input device, a control device, and an output device through a wire harness (hereinafter simply “harness”) needs to be checked, after the system has been assembled, as to whether the electrical wires composing the harness are connected in a proper route. However, when the system has large numbers of harnesses (wires) and terminal devices, such as input devices, or relay devices, it is not easy to check the validity of the connection route from a wiring diagram spreading over multiple sheets, or to confirm the safety of the wiring.
Therefore, the present applicants have hitherto proposed the following systems: a wiring connection check system whereby persons other than the system designer can easily check a connection route by the unit of a single wire even when the wiring system is large (Japanese Patent No. 5182973); a system whereby those harnesses at risk of including a combination of electrical wires which are not allowed to fail at the same time and those harnesses at risk of impairing the safety if they fail at the same time are easily extracted (Japanese Patent Laid-Open No. 2014-61841); and a system whereby the safety of wiring can be qualitatively analyzed even when the wiring structure is complicated (Japanese Patent Laid-Open No. 2014-194676).
The techniques proposed in the above disclosures are based on a principle that information showing the connection of any complicated wiring can be summarized into information on either of the following (a) and (b):
(a) Connector and electrical wire
(b) Connector and terminal device or relay device
To efficiently and concurrently check the operation of a large wiring system including a harness after the system has been designed, a common procedure is dividing the entire system into sub-systems and, after obtaining confirmation by a test in each sub-system, finally checking the operation by an actual machine test with all the wires assembled.
Especially when it is necessary to perform a test inside a limited closed space, tests by the unit of a sub-system are essential. Examples of the closed space referred to here include a thermostatic chamber when performing a temperature environmental test on the entire test device and a sound resonating chamber when performing an electromagnetic wave/lightning protection test.
While it is in principle possible to perform a sub-system test using an actual harness as is, due to restrictions on the space where the test is performed etc., devices other than those to be evaluated and unnecessary harnesses need to be excluded from the sub-system test.
The following are two possible plans for selecting only those harnesses that are necessary for a test.
Plan 1: Use as is an actual harness to be energized in a sub-system test, with branch cables which have no connection destination in the actual harness physically disconnected from their branch points or provided with a shield cap to prevent noise contamination at the connector of the terminal end of the branch. A prerequisite for physical disconnection is that no electrical wires are energized at the disconnection point. Since a multicore wire cannot be disconnected if even one electrical cable thereof is energized, a shield cap is provided.
Plan 1 is a preferable test form in that an actual machine is simulated since an actual harness is used as it is, but the test scale is large due to the inclusion of harnesses which are not directly involved in the test.
Plan 2: Redesign an actual harness to be energized in a sub-system test into a harness in which only those electrical wires that are to be energized in the test are left while all the unnecessary (non-conducting) electrical wires are removed, and use the redesigned harness as a test harness.
In Plan 2, the test scale is smaller since electrical wires unnecessary for the test are removed, but the test conditions are severer in that a lightning protection current flowing through each electrical wire becomes larger for the reduced number of the electrical wires since the lightning protection current flowing through the entire electrical wire bundle remains the same.
In both plans, it has been extremely difficult to find out which harnesses and electrical wires are necessary for a sub-system test by following the connection state in a huge number of harness drawings. Moreover, since the connection state of each of core wires composing a harness cannot be discerned by appearance as shown in FIG. 18, it is unclear which wire can be removed.
It is therefore an object of the present invention to provide a device which can determine, by the unit of an electrical wire bundle, which wire route is composed of electrical wires and connectors necessary for a test harness from design data about a wiring system employed in an actual machine.